In our earlier work, competitive Web Services market was proposed to address the hierarchical structure of large scale service systems. To better reflect the business reality, we model this system using finite capacity queues. To give the service provider more flexibility in controlling the priority level of incoming requests, we propose a performance oriented management architecture based on admission controller in this paper. Moreover, we study the design of an adaptive admission controller based on Markov decision processes and investigate the stationary policy based on different performance requirements.